Well, as I've slaughtered many wraid in a single game, it has nothing to do with seeing a dragon. That's related to the sand people/StarMap sidequest. However, there may be a mod that allows you to generate a dragon if you'd like to fight one.

Now, I want you to remember that no bastard ever won a war by dying for his country. He won it by making the other poor, dumb bastard die for his country.---Patton

There is no room in this country for hyphenated Americanism.---Teddy Roosevelt

I never forget a face, but in your case I'll make an exception.---Groucho

And if you all get killed, I'll piss on your graves.---Shaman Urdnot

How would you like to own a little bit of my foot in your ass.---Red Foreman